Сorrect partitioning

I've highlighted on the Dev cwp to 65 GB
plans to allocate storage sites 50GB, 15GB reserved for the system.
But fill sites, I noticed that the place is divided properly.
How to share the place? And how to make repartitioning?

Partition info:
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_mainhost-lv_root
                       50G   10G   37G  22% /
tmpfs                  24G     0   24G   0% /dev/shm
/dev/sda1             477M   57M  396M  13% /boot
/dev/mapper/vg_mainhost-lv_home
                      7.8G  7.4G   16M 100% /home